The nand-ecc-mode DT binding is depracated but the new bindings are
not supported by kernel 5.4. Based on a fix in the kernel to not
overwrite the DT ECC settings, the DT needs to be updated and moves
to the new DT binding.
Since the DT is shared between kernel 5.4 and 5.10, this patch is
an interim solution to allow to use the new DT bindings in kernel 5.4.
It should be removed when moving away from kernel 5.4.
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4851,10 +4851,17 @@ static int of_get_nand_ecc_mode(struct d
 {
 	const char *pm;
 	int err, i;
+	struct device_node *eng_np;
 
 	err = of_property_read_string(np, "nand-ecc-mode", &pm);
-	if (err < 0)
+	if (err < 0) {
+		if (of_property_read_bool(np, "nand-use-soft-ecc-engine"))
+			return NAND_ECC_SOFT;
+		eng_np = of_parse_phandle(np, "nand-ecc-engine", 0);
+		if (eng_np && (eng_np == np))
+			return NAND_ECC_ON_DIE;
 		return err;
+	}
 
 	for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
 		if (!strcasecmp(pm, nand_ecc_modes[i]))